The interface uses a general purpose 68705 microprocessor for the low level
signal processing; all signal processing code was written in 68705 assembler.
As there was no 68705 assembler, I had to write one, for which I used Lattice
C. The circuit design was done in Electron, a schematic capture system I wrote,
also in C; and the PCB was laid out using a combination of Electron and
Boardmaster, a PCB layout and routing system I also wrote in a combination of C
and 68000 assembler. The Amiga side software for the AVT was written in 68000
assembler and Lattice C; nothing inline, strictly isolated functions. The CPU
programmer for the 68705 was also a design of mine, although done years
previous when working for another company. The AVT's machine code was sent to
the CPU programmer using a programming utility I wrote (again in C.) Basically,
the only pre-existing tools used that I didn't create myself were Metacomco's
68000 assembler, the Lattice C compiler, and Rick Stiles' UEDIT.

The AVT system won technical achievement of the year at the Dayton ARO
gathering after its initial release. I still hear these on the air from time to
time on 14.230 and 14.233 MHz, which gives me pause to smile a bit.

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